1. Field of the Invention
The present invention relates to polypeptides having amino acid sequences related to the preacetylcholine receptor-.alpha. of the electric organ of Torpedo californica. These polypeptide sequences are useful for the production and purification of antibodies to the receptor acetylcholine receptor, as well as, for the diagnosis of myastenia gravis (MG).
2. Description of the Prior Art
Myastenia gravis (MG) is a neuromuscular disorder manifested by muscular weakness and fatigability. Recent studies suggest physiological and immunological involvement of the muscle acetylcholine receptor (AChR) in MG (See Patrick and Lindstrom, Science 180:871 (1973), and Fambrough et al, Science 182:294 (1973)).
Almon et al, Science 186:55 (1974), demonstrated the presence in some MG patients of circulating globulins with affinity for the muscle AChR.
Lindstrom et al, Annals of the New York Academy of Science: 254-274, (1976), confirmed the existence of antibodies to AChR in MG patients, as well as in an animal model for this disease. In addition, this reference describes an antibody assay for the detection of anti AChR proteins in the blood of MG patients using human AChR protein radiolabeled with .sup.125 I-Toxin.
One particularly useful modification of interest to those of skill in this art, would be to develop peptides having AChR-like activity. These polypeptides having AChR antigenic activity could be useful in the production of antibodies to the AChR protein and affinity purification thereof, as well as in the measurement of antibody levels in the blood of patients suspected of suffering from MG. These polypeptides, having high specific affinity for anti AChR protein molecules, may also be useful in the treatment of MG in mammals, including humans.
A need therefore continues to exist for polypeptides useful for the production of anti AChR antibodies, and for the affinity purification, thereof especially for the diagnosis of MG in humans.